So what do you think this will cost and where would it be best purchased, i have looked around at the usual suspects and just wondered if anyone had any other suppliers.

Rick

r0bsk1

27-10-2012, 12:15 AM

This may be of use to you.....
8x4 CNC Router Machine Kit | eBay (http://www.ebay.co.uk/itm/281010762272?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649)

Nowt to do with me. Just noticed it was recently listed.

Ricardoco

27-10-2012, 12:35 AM

This may be of use to you.....
8x4 CNC Router Machine Kit | eBay (http://www.ebay.co.uk/itm/281010762272?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649)

Nowt to do with me. Just noticed it was recently listed.

Cheers for that but i suspect that is a little too much kit and a lot too much money for my walet...LOL

But cheers anyhow

Jonathan

27-10-2012, 05:00 PM

Have you bought the ballscrews yet and/or decided how to drive the longest axis as I remember discussing it in a previous thread?

Are you going to add some pieces of box section in at 45 degrees at the front and back of the frame to make it stronger and stop it turning into a parallelepiped under high acceleration? I'd also add at least one vertical support in the middle, assuming you're planning on cutting aluminium as otherwise it wont make a tangible difference. Looks like a strong base otherwise.

How are you mounting the 2100mm rails such that they are not bent beyond tolerances? The rails I have for my machine are 2200mm so I've been planning on using self levelling epoxy to get the required accuracy.

There's some good stuff in that eBay link, however the price he says he paid for the spindle implies he got the parts from England not China, so he'll be expecting closer to England prices...

Anyway, to answer the question, you'll struggle to find the longest rails on eBay for a reasonable price, but it shouldn't be difficult to find a good deal on the 400mm rails. Clearly search for worldwide listings. 15mm rails will be fine, just make sure you get ones which have 4 rows of balls not 2.

Ricardoco

27-10-2012, 10:55 PM

Have you bought the ballscrews yet and/or decided how to drive the longest axis as I remember discussing it in a previous thread?

Are you going to add some pieces of box section in at 45 degrees at the front and back of the frame to make it stronger and stop it turning into a parallelepiped under high acceleration? I'd also add at least one vertical support in the middle, assuming you're planning on cutting aluminium as otherwise it wont make a tangible difference. Looks like a strong base otherwise.

How are you mounting the 2100mm rails such that they are not bent beyond tolerances? The rails I have for my machine are 2200mm so I've been planning on using self levelling epoxy to get the required accuracy.

There's some good stuff in that eBay link, however the price he says he paid for the spindle implies he got the parts from England not China, so he'll be expecting closer to England prices...

Anyway, to answer the question, you'll struggle to find the longest rails on eBay for a reasonable price, but it shouldn't be difficult to find a good deal on the 400mm rails. Clearly search for worldwide listings. 15mm rails will be fine, just make sure you get ones which have 4 rows of balls not 2.

As usual Jonathan, all the right questions, firstly i will be using rotating ballnuts rather than rotating ballscrews and these will provided by YOU when the time comes as discussed previously,and the frame its self will have the advantage of a welded steel box 100mm deep 2mm thick to contain water, and re-inforced with 50mmX50mm angle iron every 18", this will be for the plasma cutter, this also when used as a router will have a removable bed made from tig'ed 40mmX40mm extruded aluminium profile, the gantry will be reinforced with 3mm steel along its complete length at the rear of the two 100mmx50mmx3mm gantry parallels although this is overkill by any streach of the imagination, and certainly stronger than the usual aluminium profile used to build this type of machine, including the last one of this size i made from aluminium, which did the job perfectly. But what i was really looking for was prices for the rails not advice on the build as the question would indicate.
the problem with importing rails, is the length, is a problem as stated by the overseas suppliers i have contacted.

Rick

Jonathan

27-10-2012, 11:24 PM

That sounds like a good plan. Combining the router with a plasma (or laser) cutter is something I've been thinking of doing, since now I have an aluminium bed it wouldn't take much more to convert.

Anyway, rails...I've got some brand new 15mm NSK rails with flanged bearings blocks (LAH15) spare. Four 520mm rails and eight blocks. I got them to make a small machine, but I don't think that's going to happen any time soon so I'll sell them for the right price...Seems a shame to cut them so if you can increase the bearing spacing by 120mm you'll get the same travel as with the planned 400mm rails, but with a decent increase in rigidity through having reduced the force on each bearing block.

About the other rails, PM sent...

Ricardoco

28-10-2012, 05:02 PM

That sounds like a good plan. Combining the router with a plasma (or laser) cutter is something I've been thinking of doing, since now I have an aluminium bed it wouldn't take much more to convert.

Anyway, rails...I've got some brand new 15mm NSK rails with flanged bearings blocks (LAH15) spare. Four 520mm rails and eight blocks. I got them to make a small machine, but I don't think that's going to happen any time soon so I'll sell them for the right price...Seems a shame to cut them so if you can increase the bearing spacing by 120mm you'll get the same travel as with the planned 400mm rails, but with a decent increase in rigidity through having reduced the force on each bearing block.

About the other rails, PM sent...

Well that cuts down the bits i will be needing for sure, I will PM you asap..